>+
>+static struct objpool_head ptr_pool;
>+static int nr_objs = 512;
>+static atomic_t nthreads;
>+static struct completion wait;
>+static struct page_frag_cache test_frag;
>+
>+static int nr_test = 5120000;
>+module_param(nr_test, int, 0600);


"S_IRUSR | S_IWUSR" is better than "0600".


>+MODULE_PARM_DESC(nr_test, "number of iterations to test");
>+
>+static bool test_align;
>+module_param(test_align, bool, 0600);
>+MODULE_PARM_DESC(test_align, "use align API for testing");
>+
>+static int test_alloc_len = 2048;
>+module_param(test_alloc_len, int, 0600);
>+MODULE_PARM_DESC(test_alloc_len, "alloc len for testing");
>+
>+static int test_push_cpu;
>+module_param(test_push_cpu, int, 0600);
>+MODULE_PARM_DESC(test_push_cpu, "test cpu for pushing fragment");
>+
>+static int test_pop_cpu;
>+module_param(test_pop_cpu, int, 0600);
>+MODULE_PARM_DESC(test_pop_cpu, "test cpu for popping fragment");
>+
>+static int page_frag_pop_thread(void *arg)
>+{
>+	struct objpool_head *pool = arg;
>+	int nr = nr_test;
>+
>+	pr_info("page_frag pop test thread begins on cpu %d\n",
>+		smp_processor_id());
>+
>+	while (nr > 0) {
>+		void *obj = objpool_pop(pool);
>+
>+		if (obj) {
>+			nr--;
>+			page_frag_free(obj);
>+		} else {
>+			cond_resched();
>+		}
>+	}
>+
>+	if (atomic_dec_and_test(&nthreads))
>+		complete(&wait);
>+
>+	pr_info("page_frag pop test thread exits on cpu %d\n",
>+		smp_processor_id());
>+
>+	return 0;
>+}
>+
>+static int page_frag_push_thread(void *arg)
>+{
>+	struct objpool_head *pool = arg;
>+	int nr = nr_test;
>+
>+	pr_info("page_frag push test thread begins on cpu %d\n",
>+		smp_processor_id());
>+
>+	while (nr > 0) {
>+		void *va;
>+		int ret;
>+
>+		if (test_align)
>+			va = page_frag_alloc_align(&test_frag, test_alloc_len,
>+						   GFP_KERNEL, SMP_CACHE_BYTES);


Every page fragment max size is PAGE_FRAG_CACHE_MAX_SIZE,
hence the value of test_alloc_len needs to be checked.


>+		else
>+			va = page_frag_alloc(&test_frag, test_alloc_len, GFP_KERNEL);
>+
>+		if (!va)
>+			continue;
>+
>+		ret = objpool_push(va, pool);
>+		if (ret) {
>+			page_frag_free(va);
>+			cond_resched();
>+		} else {
>+			nr--;
>+		}
>+	}
>+
>+	pr_info("page_frag push test thread exits on cpu %d\n",
>+		smp_processor_id());
>+
>+	if (atomic_dec_and_test(&nthreads))
>+		complete(&wait);
>+
>+	return 0;
>+}